/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.context.annotation;

import java.util.Set;

import org.w3c.dom.Element;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.parsing.BeanComponentDefinition;
import org.springframework.beans.factory.parsing.CompositeComponentDefinition;
import org.springframework.beans.factory.xml.BeanDefinitionParser;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.lang.Nullable;

/**
 * Parser for the &lt;context:annotation-config/&gt; element.
 *
 * @author Mark Fisher
 * @author Juergen Hoeller
 * @author Christian Dupuis
 * @see AnnotationConfigUtils
 * @since 2.5
 */
public class AnnotationConfigBeanDefinitionParser implements BeanDefinitionParser {

    @Override
    @Nullable
    public BeanDefinition parse(Element element, ParserContext parserContext) {
        Object source = parserContext.extractSource(element);

        // Obtain bean definitions for all relevant BeanPostProcessors.
        Set<BeanDefinitionHolder> processorDefinitions =
                AnnotationConfigUtils.registerAnnotationConfigProcessors(parserContext.getRegistry(), source);

        // Register component for the surrounding <context:annotation-config> element.
        CompositeComponentDefinition compDefinition = new CompositeComponentDefinition(element.getTagName(), source);
        parserContext.pushContainingComponent(compDefinition);

        // Nest the concrete beans in the surrounding component.
        for (BeanDefinitionHolder processorDefinition : processorDefinitions) {
            parserContext.registerComponent(new BeanComponentDefinition(processorDefinition));
        }

        // Finally register the composite component.
        parserContext.popAndRegisterContainingComponent();

        return null;
    }

}
